For what its worth....from a Maker point of view.......
San mai is pretty and made in an interesting and more artful way than grinding a piece of mono steel, though that is artful too of course......... I tend to think the joy of creating something is reflected in the beauty of the object.
The Metallurgy becomes exciting visually and practically.
Using stainless clad and high carbon core, you will loose a percentage of carbon to the soft stainless cladding. You can either make the core a bit thicker so you have a certain amount as sacrificial carbon...Use a steel which could work well with slightly less carbon......Or add a layer of pure nickel to keep the carbon in the core. Of course that way you have a crisp weld line without the frosty hamon-esc effect. Either way you get something pretty special and unique.
Structurally, the blade does feel different. For example a soft clad san mai can be straightened with relative ease with hammer and stump with the core 62 hrc plus. Mono would demand far more care if you were working out a warp post heat treatment. This should tell you something about the feel and toughness of the blade. Though it will have relatively little effect in supporting the very edge it could help stop a huge chip in a very extreme situation. Though realistically this can all be optimized with good heat treatment in mono steel for our practical uses.
To me using different materials in a knife either in san mai or a composite construction is like having a differential heat treatment. You can have the spine or cladding softer than the the core or edge weld. And it might not be completely soft, I often use steels that temper differentially, looking for a core which is 60 plus while the cladding or spine is less than 58 hrc. Or medium carbon steel less than 55 hrc.
But these are not for use as swords granted where the extra toughness and flex would be a great advantage, so its largely a joy of the art in doing it thing. And the knowledge that you blade has an optimal construction.
Soft or softer clad knives are easier to grind and sharpen or at least thin, though also easier to mark the cladding in use.
You can use a combination of stainless clad and carbon core, thats probably one of the nicest advantages in practical use.
Umm and it look purty....did I mention that